I don’t think I’m capable of saying who this passage is referring to, or when this time period will take place. I haven’t studied prophecy – the whole Bible – enough. What I can see however, is what God is capable of doing.
God can make His light shine through his people, even in thick darkness. What is this light?
This light is love in action – love for God and love for people. It is this love that compells one to bring God’s justice, mercy, grace. This is the true light – it is not merely the absence of sin, or the (passive) goodness of one’s heart. This is the kind of light that attracts peoples, nations. It makes them recognize the goodness of God, and moves them to contribute to His cause through you. And those who oppose you – those who oppose God by causing injustice – they will be brought low. Then there will be peace, there will be joy.